Sound-box



F. N. GREEN.

SOUND BOX.

APPLICATION FILED 1 58.13, 1920.

Snvewbqz UNITED STATES PATENT OFFICE.

SOUND-BOX.

Specification of Letters Patent.

Application filed February 13, 1920. Serial No. 358,348.

To all whom it may concern:

Be it known that I, FREnnIoK N. GREEN, a citizen of the United States, resldmg at Willimantic, in the county of Windham and-- companying drawing.

This invention relates to improvements in sound boxes for talking machines, and particularly pertaining. to talking machines of the well-known Victor and the Columbia t e. ne object of my invention isto provide a sound box composed of wood, whereby a more natural and accurate reproduction of the sound waves on the record is produced; and also for the purpose of materially reducing the scratching noise common to metal sound boxes, and to thereby reduce the weight of the sound box, which reduces the wear on both. the record and the needle, whereby both are lon er lived.

A further object o my present invention is to provide a sound box having a main or needle diaphragm and an outer auxiliary diaphragm carried by an auxiliary sound box which is connected to the main sound box, which materially increases the sound waves or vibrations made by the main diaphragm by forcing the sound wave or vibrations in increased volume through the tone arm connection. This auxiliary diaphragm and sound box in addition to increasing the volume, also'serves to modulate the tone of the main diaphragm to a more natural voice tone, preventing the common unnatural high pitch of certain sound waves and material if not entirely, preventing what may be called blasting sound waves, which are common with metal sound boxes when reproducing certain sound waves.

Further objects of my resent invention will appear from the description hereinafter given.

In the accompanying drawings- Figure 1 is a perspective view of my improved sound box showing it supported in relation to a disk record and a part of the tone arm.

Fig. 2 is a central transverse sectional view through my improved sound box.

, Fig. 3 is a front elevation of Fig. 2.

The mainbox 1 in my improvement, is,

composed of wood and has its inner side provided with a sound outlet opening 2, formed by an inwardly extending annular flange 3. 7 Connected with this flange 3 is the usual combined rubber and metal tone arm connecting member 4, which in the instance here shown is attached to the flange 3, by suitable screws 5 passing through the member 4 into the flange 3. The main wood box 1, has an outwardly extended wall 6, WhlCl'l forms an outwardly extending bellshaped recess 7. The mam diaphragm 8 closes the outer end of this recess 7 and is clamped in position between two elastic rin 9, by an annular ring or plate 10. Thls plate 10 is made to clam the diaphragm 8 with any desired tenslon by means of clamping screws 11. This adjustable means of ti htening the diaphragm against the main ox also proves to be a tone adjusting means as the degree of tightness with which the diaphragm is pressed against the box will affect the quality of the tones it produces.

I provide the main diaphragm 8 with a supplemental sound diaphragm 12, and this latter sound diaphragm is preferabl located on the outer side of the main diap ragm 8- and cemented thereto throughout the engaging surfaces of the main and center diaphragms. The approximate sizes of the main and its center diaphragms will be, the main diaphragm substantially two and one-half inches in diameter, and its center diaphragm substantially one inchin diameter. This additional center diaphragm is for the pur pose primarily of preventing blast sound waves.

y In the above construction, the needle arm 13 has its inner end 14 secured to the centers of the main diaphragm 8, and its center diaphragm 12 in the usual manner, by a suitable cement, and preferably passes through both of these diaphragms. This needle arm 13 has near its outer end outwardly extending trunnions15,which receive the inner ends of the adjustable pivots 16..

These adjustable pivots pass through inwardlyextending arms 17 which project .from'a plate 18 that is attached to the periphery of the main wood box 1, in'any Patented Mar. 22, 1921.

box the needle support consists of the arm 17 carried by the plate 18. and is composed of soft brass, which helps to clarify the tone and eliminate the so-called needle scratch. which is objectionable and quite common to talking machines.

Another feature of in present improvement is an auxiliary iaphragm box 20. which is secured to the sound box 1, through the medium of copper arms 21, which have their opposite ends respectively attached to the main box 1, and the auxiliary box 20. Preferably there are four of these copper arms 21. The inner side or this auxiliary diaphragm box 20 is provided with a recess 22, which constitutes what may be termed a bowl-shaped sound box or body. This auxiliary box 20 carries an auxiliary diaphragm 23, which rests against the bottom 24 of the recess 22, and is secured therein by a suitable wax cement 25 applied at its inner side around its periphery and between it and the side wall of the recess 22. The auxiliary diaghragm 23, like the main diaphragm 8, is provided with a central diaphragm 26, which is cemented to'the inner side of the diaphragm 20 with any suitable cement. The auxiliary box 20 is provided with a central opening 27 and the bottom of the box 20 is recessed from a point approxi mate the periphery of the inner diaphragm 26 to the opening 27, as shown at 28, thus forming a concaved recess 29 opposite the centers of the diaphragms 24 and 26, and in direct line with the centers of the main diaphragm 8 and center diaphragm 12.

The auxiliary diaphragm 24 is of less diameter than the main diaphragm 8, while the center diaphragms 8 and 26 are approximately of the same diameter. The auxiliary diaphragm box 20 is also smaller in diameter than the main sound box 1.

A' wood sound box is, of course. relatively light and for the purpose of adding just suflicient weight thereto to hold the needle in the record groove and to prevent it from skipping or jumpingl from one groove to the other, I add just su cient weight to the box to insure the needle staying in its groove. This weight consists of a ring 9, placed around the flange 3 of the main BOX 1. While this weight. of course, increases the weight of the sound box. yet the whole structure is .ighter than such a structure would be if made of metal.

3 desire it to be understood that my improved sound box may be made of any desired size and that the dimensions mentioned in the preceding description are not to be taken as any limitation of the invention.

Furthermore. by reason of the wood box. .t can be given any desired finish to match the case or cabinet containing the instrument.

Having thus described my invention, what l claim and desire to secure by Letters Patent is:

L. An improved sound box. comprising a main box with a central sound opening, a diaphragm closing the outer end of the opening, an auxiliary box supported in front of and away from the diaphragm of the main box. and a diaphragm carried by the auxiliary box. for the purpose described.

2. An improved sound box, comprisinga main box with a central sound opening, a diaphragm carried by and closing the outer end of the opening, an auxiliary box supported in front of and separated from the main box. a diaphragm in the auxiliary box, and a sound opening in the auxiliary box opposite the opening in the main box, as described.

3. An improved sound box. comprisin a main box having a sound opening, a (la- ;hragm closing the outer end of the said opening, an auxiliary box of approximately the same size as the main box sound opening, a diaphragm in the auxiliary box, a sound opening in the auxiliary box, and arms supporting the auxiliary box from the main iox in a position in front of and separated from the main box opening so as to provide a passage for sound waves across the face of the main box and around the edges or" the auxiliary box.

In testimony whereof I hereunto affix my signature.

FREDRICK N. GREEN. 

